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Home >> Jeep >> 2018 >> Grand Cherokee Laredo, RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 8 (3.0L Diesel - DTCS P0627-00 To P1692-00) >> DTC Troubleshooting >> P0647-00-A/C Control Circuit High >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different variant/trim than selected.
  1. CHECK FOR AN ACTIVE DTC 
    1. Ignition on, engine not running.
    2. With the scan tool, erase DTCs in the PCM.
    3. Crank the engine for no more than 10 seconds if it will not start.
    4. With the scan tool, select View DTCs.

      Is the status Active for this DTC?

      Yes 

      • Go To  2

      No 

      • Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT DTC .
  2. CHECK THE A/C CLUTCH RELAY FOR PROPER OPERATION 
    1. Turn the ignition off.
    2. Replace the A/C Clutch Relay (in the Power Distribution Center) with a known good relay.
    3. Turn the ignition on.
    4. With the scan tool, erase DTCs in the PCM.
    5. Start the engine or crank the engine for 10 seconds.
    6. With the scan tool, select View DTCs.

      Did the DTC return?

      Yes 

      • Go To  3.

      No 

  3. CHECK THE (C13) A/C CLUTCH CONTROL CIRCUIT FOR A SHORT TO ALL OTHER CIRCUITS IN PCM 1 CONNECTOR 
    1. Turn the ignition off.
    2. Disconnect the PCM C1 harness connector.
    3. Measure the resistance between the (C13) A/C Clutch Control circuit and all other circuits at the PCM C1 harness connector.

      Is the resistance above 10k Ohms between the (C13) A/C Clutch Control circuit and all other circuits?

      Yes 

      • Go To  5

      No 

      • Go To  4
  4. CHECK THE (C13) A/C CLUTCH CONTROL CIRCUIT FOR A SHORT TO ANY OTHER CIRCUITS IN THE PCM1 CONNECTOR 
    1. Disconnect the PDC harness connectors.
    2. Measure the resistance between the (C13) A/C Clutch Control circuit and all other circuits at the PCM C1 harness connector.

      Is the resistance above 10k Ohms between the (C13) A/C Clutch Control circuit and all other circuits?

      Yes 

      • Replace the Power Distribution Center (PDC) in accordance with the service information.
      • Perform the PCM VERIFICATION TEST. Refer to PCM VERIFICATION TEST .

      No 

      • Repair the (C13) A/C Clutch Control circuit for a short to the circuit that measured below 10k Ohms.
      • Perform the PCM VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
  5. CHECK RELATED HARNESS CONNECTIONS 
    1. Disconnect all PCM harness connectors.
    2. Disconnect all related in-line harness connections (if equipped).
    3. Disconnect the related component harness connectors.
    4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • Bent terminals.
      • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
      • Terminals that have been pushed back into the connector cavity.
      • Check for spread terminals and verify proper terminal tension.

      Repair any conditions that are found.

    5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
    8. With the scan tool, erase DTCs.
    9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
    10. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      No 

      • Repair the poor connections.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .